BOTAONE Module 5-7 (Long Exam 2) - NOT comprehensive

Photosynthesis, Cellular Respiration, & Cell Division

van Helmont

person who discovered that:

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plant matter comes from __water__ alone

Priestley

person who discovered that:

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plants produce **O2** = __dephlogisticated air__

Senebier

person who discovered that:

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photosynthesis depends on **CO2** = __fixed air__

Lavoisier

person who discovered that:

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O2 & CO2 involved in photosynthesis

Saussure

person who discovered that:

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water is an important requirement in

photosynthesis;

CO2 + H2O + light → organic matter + O2

Engelman

person who discovered that:

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red & blue light are effective in producing O2

Sachs

person who discovered that:

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chlorophyll is in photosynthesis

Niel & Hill

person who discovered that:

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O2 from H2O (Hill’s reaction / photolysis) in

photosynthesis

contemporary botanists

person who discovered that:

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final electron acceptor of photosynthesis is NADP+

Oxidation

Redox:

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* adding O
* removing H
* loss of Electrons
* releases energy
* exergonic

Reduction

Redox:

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* removing O
* adding H
* gain of Electrons
* stores energy
* endergonic

Chlorophyll a

Photosynthetic pigment:

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* main photosynthetic pigment
* for ALL __photosynthetic__ organisms
* in ALL __autotrophic__ organisms
* w/ CH3

accessory pigments

Photosynthetic pigment:

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* absorb different wavelengths of light & __pass the energy__ to chlorophyll a
* broaden spectrum used for photosynthesis

Chlorophyll b

accessory pigments:

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* in ALL true plants
* *w/ CHO*

Chlorophyll c

accessory pigments:

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in golden brown & brown algae

Chlorophyll d

accessory pigments:

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in red algae (ex. nori)

Porphyrin ring & Hydrocarbon tail

parts of Chlorophyll

Carotenoids

accessory pigments:

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* pigment present in ALL photosynthetic organisms
* protectors of chlorophyll molecules
* **absorb high energy radiation** prior

thylakoid membrane

where light reaction occurs

P680+

in Non-Cyclic Electron Flow of Photosynthesis:

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strongest biological oxidizing agent

plastoquinone, Cytochrome complex, & plastocyanin

proteins in 1st ETC in Non-Cyclic Electron Flow of Photosynthesis

Ferredoxin & NADP+ reductase

proteins in 2nd ETC in Non-Cyclic Electron Flow of Photosynthesis

stroma

where Calvin cycle occurs

phosphoglyceric acids

substance in Calvin cycle:

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* PGA
* 3C

glyceraldehyde-3-phosphate

substance in Calvin cycle:

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* G3P
* 3C

ribulose phosphate

substance in Calvin cycle:

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* RP

ribulose biphosphate

substance in Calvin cycle:

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* RuBP
* 5C

6CO2, 12PGA, 12G3P, 1 glucose, 6RP, & 6RuBP

transformation of 6CO2 in Calvin Cycle

CO2 uptake, Carbon reduction, & RuBP regeneration

3 phases in Calvin Cycle

Rubisco

enzyme that triggers carbon acceptance of CO2 in photosynthesis

photorespiration

* __breakdown of sugars to CO2__
* undos photosynthetic efficiency of Calvin cycle by 50%
* from Rubisco as an oxygenase

C4 Pathway

* aka Hatch-Slack Pathway
* hot, moist environments
* 15% of plants (some grasses, corn, sugarcane)
* divides photosynthesis **spatially**
* in mesophyll cell & bundle-sheath cell

Phosphoenolpyruvate carboxylase

* PEP carboxylase
* 3C

CO2, Oxaloacetate, Malate, & Pyruvate

* transformation of CO2 in C4 Pathway
* COMP

Crassulacean acid metabolism Pathway

* CAM Pathway
* hot / cold but dry environment
* 5% of plants (cactus & ice plants)


* similar to C4 pathway
* **temporal separation** of steps
* everything in __mesophyll__ cells

night

time in CAM pathway:

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* stomates are open
* CO2 enters and is converted to __Malate__
* stored in cell vacuoles as __malic acid__

day

time in CAM pathway:

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* stomates are closed
* to protect from heat
* when light reaction occurs
* CO2 is removed from Malate & undergo Calvin Cycle (when CO2 is present)

Cellular Respiration

- type of catabolic pathway
- opposite formula to photosynthesis
- includes both aerobic & anaerobic respiration
- carbs, fats, and proteins are all consumed as fuel

Adenosine Triphosphate (ATP)

- energy for all cells
- “energy currency” of the cell
- releases large amounts of energy when converted to adenosine diphosphate (ADP)

Glycolysis

* breaks down glucose (or other carbs) into 2 pyruvates
* occurs in the **cytoplasm**
* has 2 major phases: energy investment phase & energy payoff phase
* may occur with or without oxygen
* produce 2 ATP
* **Substrate-Level Phosphorylation**
* universally found in ALL organisms

Fermentation

* type of anaerobic respiration that uses substrate-level phosphorylation instead of ETC to produce ATP
* when O2 is NOT available → **anaerobic** process
* pyruvate undergoes __reduction__
* consists of:
* Glycolysis
* reactions that generate NAD+
* can be reused by glycolysis

lactic acid

product of fermentation in animals

alcohol

product of fermentation in plants

Alcohol Fermentation

* pyruvate converted to **ethanol** in 2 steps
* first __releases CO2__
* final electron acceptor: **Acetaldehyde** ☠
* 2 ATP = 14.6 kcal → 2.1% efficiency compared to CR

Acetaldehyde

final electron acceptor in Alcohol Fermentation

Acetyl CoA Formation

* connects glycolysis to CAC
* 2 pyruvate (C3) → 2 acetyl CoA (C2)
* 2 CO2 released
* 2 NAD+ → 2 NADH + 2 H+
* transition occurs **twice**

Citric Acid Cycle

* aka Krebs Cycle or Tricarboxylic Acid Cycle
* cyclic metabolic pathway in mitochondrial **matrix**
* produce 2 ATP

Acetyl CoA, citrate, ketoglutarate, succinate, fumarate, & oxaloacetate

* transformation of Acetyl CoA in Krebs Cycle
* ACKSFO

Oxidative Phosphorylation

* has electron transport chain and chemiosmosis
* ATP synthesis / production
* occurs at the **cristae** of mitochondria
* generates most ATP (almost 90%)
* powered by redox reactions

Electron Transport Chain

* in **cristae**
* series of electron carrier proteins that pass electrons
* __proton gradient__ from redox reactions
* H+ gradient = **proton-motive force**
* energy released to form **ATP** in Chemiosmosis
* electrons from __NADH & FADH2__
* forms **water**

oxygen

final electron acceptor of ETS

Chemiosmosis

- major source of ATP
- use of energy in a H+ gradient to drive cellular work
- proteins to pump H from the mitochondrial matrix to the intermembrane space
- H moves back across the membrane, passing through the protein ATP synthase
- ATP synthase uses exergonic flow of H (spinning of H in rotor) to drive phosphorylation of ATP
- produce ~26-28 ATP

\~30-32 ATP, 6CO2, & 6H2O

output of Cellular Respiration from 1 glucose

Respiration of Lipids

* *glycerol* → glycolysis for degradation
* *fatty acids* → acetyl CoA
* produces more than twice the energy from glucose

Respiration of Proteins

* broken down to __amino acids__
* **deaminated** = remove amino group
* becomes ammonia (NH3) & is excreted
* **remaining carbon portion**
* enters respiration in various ways

Temperature, Molecular Oxygen, CO2 concentration, State of Hydration, Age & Type of Tissues

Factors affecting Cellular Respiration

G1 Phase

phase in the cell cycle:

- 1st Gap
- increase cell growth
- increase in number of cytoplasmic structure (mitochondria & skeletal structure)
- doubling in number of centrosomes
- cell will know their role

S Phase

phase in the cell cycle:

DNA synthesis

G2 Phase

phase in the cell cycle:

- 2nd gap
- biochemical preparation for the onset of mitosis

G0 Phase

phase in the cell cycle:

- Gap Phase
- normal stage
- will NOT go to mitosis
- nerve or heart muscle cells

cohesins

proteins that attach sister chromatids at __centromere__

kinetochore

protein that attach sister chromatids to __spindle fibers__

Binary Fission

type of cell division:

- done by prokaryotes
- produces 2 daughter cells

centrioles

microtubules in animal cell

phragmoplast

microtubules in plant cells

homologs

- homologous chromosomes
- 2 chromosomes in a pair
- same length & shape
- carry genes controlling the same inherited characters

Chiasmata

- x-shaped regions
- site of crossover
- turns into recombinant chromosomes
- forms during Prophase I in Meiosis

synapsis

pairing of homologous chromosomes

G1 checkpoint

checkpoint in the cell cycle:

- most important checkpoint
- signals if cell continues the cell cycle or enters G0

M checkpoint

checkpoint in the cell cycle:

- occurs after Metaphase, before Anaphase
- checks if chromosomes are fully attached

regulatory proteins

- cyclin & cyclin-independent kinase (Cdk)
- activity of Cdk rises & falls w/ changes in concentration of its cyclin partner

maturation-promoting factor (MPF)

* cyclin-Cdk complex that triggers a cell’s passage past the G2 checkpoint into the M phase
* peak concentration during M phase

anaphase-promoting complex (APC)

* in M checkpoint
* transmit signal for anaphase to proceed

Growth Factors

External Factors that influence Cell Division:

* released by certain cells
* stimulate other cells to divide
* platelet-derived ___

Density-dependent inhibition

External Factors that influence Cell Division:

crowded cells will stop dividing

Cancer Cells

- do NOT respond to body’s control mechanisms
- do NOT need growth factors to grow and divide
- have an abnormal cell cycle control system
- may form tumors

benign tumor

type of tumor in which abnormal cells:

remain only at original site

malignant tumor

type of tumor in which abnormal cells:

- invade surrounding tissues & can metastasize
- export cancer cells to other parts of the body

transformation

normal to cancer cells

Recombinant DNA

* for genetic modification
* in Bacterial Cell Plasmid as a host
* original DNA + foreign DNA